<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			#body{height: 200px;
				border:  1px solid black;		
			
			}
			
		</style>
	</head>
	<body>
		<div id="body" ">
			
		</div>
		<input type="button" value="增高" onclick="add();" />
		<script type="text/javascript">
			function add(){
				var e=document.getElementById("body");
				var h=document.defaultView.getComputedStyle(e,null).height;
				
//				var h=e.getAttribute("height");
//				var h=e.height;
				alert(h);
				e.style.height=(parseInt(h)+10)+"px";
			}
		</script>
	</body>
</html>
